Q: i pod shuffle 4th generation

If this is a new iPod shuffle, make sure the docking cable plug is fully inserted into the iPod's headphones jack, as shown in this document

iPod shuffle (4th generation): Not seen in iTunes - Apple Support

If that's not the problem (this iPod previously worked with your computer and connected to iTunes), please reply back with more details about your situation.

When you connect the shuffle, what does its light do?  Does it come ON and blink?  Does it come ON solid (not blinking)?  It does not come ON at all?

Also, try shutting down (powering off) the computer and disconnecting all USB devices.  You can leave standard USB keyboard/mouse connected, if used.  If your computer is a laptop, connect its power adapter so that it's not running on battery power.  Put the shuffle's power switch in the OFF position.  Startup computer, run iTunes, and connect shuffle to a direct USB port on the computer, by itself.  Is there any difference?